Regeneron Pharmaceuticals, Inc.
HEAVY PEPTIDE APPROACH TO ACCURATELY MEASURE UNPROCESSED C-TERMINAL LYSINE IN ANTIBODIES

Abstract:

The present disclosure provides a method for measuring post-translational modifications in proteins such as antibodies. In particular, the method may be used to quantify C-terminal truncation in antibodies that incorporates heavy isotopic standards for both the unprocessed C-terminal K peptide and the truncated C-terminal K peptide to build a calibration curve and quantify this PTM using mass spectrometry. Quantification of post-translational modifications may occur in a single liquid chromatography tandem mass spectrometry (LC-MS.sup.2) run.